Barack Obama says the 'I' word
He said he had ordered military action in Libya to prevent a massacre that would have "stained the conscience of the world", and would have meant "the democratic impulses that are dawning across the region would be eclipsed by the darkest form of dictatorship, as repressive leaders concluded that violence is the best strategy to cling to power".
He said that that "would have been a betrayal of who we are. Some nations may be able to turn a blind eye to atrocities in other countries. The United States of America is different. And as president, I refused to wait for the images of slaughter and mass graves before taking action."
Having dealt with critics who say he's gone too far, Mr Obama turned to those who say he hasn't gone far enough.
He said the world would be a better place without Col Muammar Gaddaffi, but to widen military aims to get rid of him would have splintered the coalition and meant American boots on the ground.
"To be blunt, we went down that road in Iraq. Thanks to the extraordinary sacrifices of our troops and the determination of our diplomats, we are hopeful about Iraq's future. But regime change there took eight years, thousands of American and Iraqi lives, and nearly a trillion dollars. That is not something we can afford to repeat in Libya."
In this, he is preparing people for what may be quite a messy period, and he warned that Libya will remain dangerous until Col Gaddafi goes, that the Libyan leader may cling to power for a while, but that his people had been given "time and space" to decide their own destiny.
This is one question hanging in the air. How far is the coalition acting as the rebel air force? It may not be targeting the top man, but is it intent on destroying his military force? How thin is the line between driving off an army that may attack civilians and destroying that army in case they do?
The other question left hanging was whether there was such a thing as an "Obama doctrine", or at least a consistent approach to intervention. On the one hand, he seemed to argue against those who said America should not police the world: "There will be times, though, when our safety is not directly threatened, but our interests and values are."
However, he accepted that didn't mean action in every case. "It is true that America cannot use our military wherever repression occurs. And given the costs and risks of intervention, we must always measure our interests against the need for action. But that cannot be an argument for never acting on behalf of what's right."
So he seems to be saying, sometimes you do, sometimes you don't, take each case on its merit.
But what struck me most forcibly was the determined, confident tone of the speech. Every single news conference, sound bite or statement so far by Mr Obama has stressed that the UK and France were in the lead, the Arabs were supporting, the US was just part of a broad coalition. They've been thoughtful and a little hesitant. Those were the "on the road" snapshots. This was the air-brushed studio portrait.
Now Mr Obama repeatedly talked of the decisions he took, his leadership, his reasoning for taking firm action. The fact that the US mission is winding down and that it is handing over control to Nato was in there, but it wasn't the emphasis. Now it seems as if the action has worked, Mr Obama is claiming credit. The "I" word was to the fore, and I don't just mean Iraq.